When Deborah Fraser's credit card number was stolen, the thief didn't use it to buy a new car or a high-end laptop. Instead, the number was used to buy something potentially much more valuable--a domain name with the word "ebay" in it. In Fraser's case, that was the domain name "change-ebay.com," a scam Web site where an unknown number of eBay users may have been tricked into handing over their eBay user name and password.

"Somebody fraudulently used my credit card (Thursday) to buy the domain name that ended in 'ebay,'" said Fraser, a pharmacy technician in Lockport, N.Y., who until midday Thursday was listed as the registrant and administrative contact for the domain. "It's very upsetting to think that someone had my credit card. I don't know if I'm ever going to go on eBay again, because I don't know if it had anything to do with purchasing something there or what."

While Fraser's credit card number could have been filched anywhere, the fact remains that con artists are using stolen numbers to set up a growing population of increasingly convincing scams intended to part eBay buyers and sellers from their user names and passwords. Once a con artist has commandeered an account, the process of defrauding buyers out of potentially tens of thousands of dollars while evading detection becomes that much easier.

These scam e-mails often tell recipients that someone has tampered with their account or that some unspecified fraud is suspected. The e-mail then tells the recipient to click on a link leading to a site where visitors can enter or change their user name and password.